[fpc-pascal] fcl-web: Trequest.RemoteAddr is empty (sometimes)

Luca Olivetti luca at ventoso.org
Tue Jan 12 09:49:23 CET 2021


El 8/1/21 a les 11:14, Luca Olivetti via fpc-pascal ha escrit:
> El 8/1/21 a les 11:06, Michael Van Canneyt via fpc-pascal ha escrit:
> 
>>
>> Are you using https ?
> 
> No, plain text http.
> An even weirder fact is that I seem to get the wrong ip address (i.e. 
> the address of a different client).

I think I found the possible cause:

I have an own thread that spawns a TEmbeddedHttpServer (actually a 
derived class to manage server-sent-events, 
https://lists.lazarus-ide.org/pipermail/lazarus/2020-June/238072.html) 
with threaded:=true.

My thread has a method to manage the requests and it does this

     FRequest:=ARequest;
     Synchronize(@SyncNewConnection);
     if FCommandQueue<>nil then .....


I think that, since the method is called from a different thread for 
each request, if two requests come at the same time, the FRequest and/or 
the FCommandQueue (which is set in the synchronized method) could get 
mixed up.

I now did 2 things:

1) protected that part of the code with a critical section
2) use TThread.Synchronize(nil,..) (since it's not my thread but another one


    FCrit.Acquire;
    FRequest:=ARequest;
    TThread.Synchronize(nil, at SyncNewConnection);
    LocCommandQueue:=FCommandQueue;
    FCrit.Release;
    if LocCommandQueue<>nil then...



WDYT?

Am I right thinking that, even if several copies of the above method are 
running, each will get it's own local variables, so the LocCommandQueue 
variable (as well as the other locals) won't be clobbered by another copy?
Or should I declare them as threadvar?


Bye
-- 
Luca


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